Dyno Numbers Seem Weak?

[RedfireVert]

Just got back from the Dyno. I think the results are a little weak.

Dyno results were 413 rwhp and 410 rwt.

Stock power on the same dyno was 380 rwhp and 360 rwt.

Mods are a 2.93 pulley and CAI. I'm using the Predator with 6% timing retard (91 octane gas in CA). I really have no idea if 6% retard is optimum...I just know it keeps detonation away.

I have no idea what the A/F was. I've arranged to get a dyno tune from SoCalDiablo next month.

So are the results a little light? What should they be?

 

[PhillyCobra]

No mention of exhaust mod in your post. Would guess your numbers won't be good until you open up exhaust. Stock motor probably gains 30 hp from cat back, pullied motor should be 40 or so. Engine needs to breath out as well as in.

 

[RedfireVert]

This is true...I don't have a modded exhaust yet...I thought the cat back was only worth 12-15. I really don't know.

 

[tvguy]

Originally posted by PhillyCobra
No mention of exhaust mod in your post. Would guess your numbers won't be good until you open up exhaust. Stock motor probably gains 30 hp from cat back, pullied motor should be 40 or so. Engine needs to breath out as well as in.

Yea, no doubt. Your stock numbers rock!! Like he said I'd say they are low if you had a catback. But if you don't, add one and dyno again. You have a great base. Something doesn't seem right. Let us know if you've left anything out with your mods.
pacotaco

 

[RedfireVert]

Originally posted by pacotaco
Let us know if you've left anything out with your mods.
pacotaco

Nope, that's it for the mods...nothing more just pulley, CAI and predator.

 

[tvguy]

Originally posted by RedfireVert
Nope, that's it for the mods...nothing more just pulley, CAI and predator.

Then by all means get a catback at the very least. X-pipe or H-pipe wouldn't be a bad idea also. The stock exhaust system is killing you. Tons of air in, but a bottleneck out. Remember, an engine is just an air pump. Good luck. And like I said you have great stock #'s, so add a catback or more and you'll be loving life!!
pacotaco

 

[soniccobra 03]

Get a cat-back and watch your numbers get close to 450-460 hp........enjoy.:beer:

 

[hj16]

Originally posted by PhillyCobra
No mention of exhaust mod in your post. Would guess your numbers won't be good until you open up exhaust. Stock motor probably gains 30 hp from cat back, pullied motor should be 40 or so. Engine needs to breath out as well as in.

No. Even with stock exhaust he should be putting up much higher numbers.

With a 2.90, CAI, and Chip I put down 421/451 and that was with zero driving cycles.

He should at the very least be seeing 420/440. Your tune is probably way off.

 

[Chonger]

Only way to be sure is to check the AF. My first dyno run with the predator only got me 422/429 SAE with the 2.95 pulley. This was with a catback and x-pipe. Tune was WAY TOO rich!! From about 4000 RPM's it was running about 11.5 and then dropped off to about 10.2-10.4 real quickly. I ended up leaning the tune out 7.5% across the board to get around 11.5 from 4500 on up. My tune is still conservative but that is the way I like it.

 

[RedfireVert]

First, thanks for all the responses...no way can I build my Cobra without you guys and the knowledge you bring.

First, we can conclude that the Predator "canned tune" is probably way off. Second, some exhaust mods can help too.

To satisfy curiosity, I'll see if the engine responds to pulling out fuel.

Regardless, I'm definitely going to SoCalDiablo next month for a dyno tune.

Thanks again

- Russ

 

[eod guy]

my 2cents
soniccobra03 is on the money about the catback - big gains to be had

and Defiantly have you tune checked

 

[CobraBob]

Was it a Mustang or Dynojet dyno?

 

[ALA G8R]

Originally posted by RedfireVert
.....To satisfy curiosity, I'll see if the engine responds to pulling out fuel.

Regardless, I'm definitely going to SoCalDiablo next month for a dyno tune.

Thanks again

- Russ

I would wait to pull out fuel until you get it on the dyno.

 

[broke7]

I would bump the timing up some, monitor it and see what goes on, adjust it to about 22 degrees @ WOT of you can. I run 23.8 degrees of timing here in alaska, with 92 Octane chevron which has been proved to be 91 most of the time.

The #'s are a tad low IMOP. Its amazing what timing retard will do, I switched my chip to the stock position once on my current setup and the car felt like a turd. I think stock timing is in the 18-19 area. It would barely break the tires loose, I went back to my good tune and it blew the tires off in 2nd.

Exhaust is gonna help, not so much the Xpipe but the catback will. I made 456/472 on my stock Hpipe and catback piping with straightpipes installed. So it isnt that choked up. I was running a 2.80 upper though.

Keep us posted

 

[RedfireVenom]

Get an exhaust. I have a car just like yours. Vert redfire and I put down 413.4 RWHP with just CAI and exhaust.

 

[RedfireVert]

I've gathered more information and made some discoveries:

1) Adjusting timing retard from 6% to 4% caused detonation. I returned the setting to 6%.

2) I pulled out 8% total fuel. I can barely tell if it helps. However, adding fuel makes the car sluggish.

3) Regarding cat backs, a well respected tuner said that the basic systems were worth only 15 hp. On the other hand, the Borla Stinger was worth about 35 hp.

Another observation is that without a dyno, it's very difficult to determine if small changes to timing or fuel do anything.

Please let me know if you have additional thoughts. Otherwise, I'll keep you posted on any developments.

Russ

 

[Pyro]

Originally posted by RedfireVert
I've gathered more information and made some discoveries:

1) Adjusting timing retard from 6% to 4% caused detonation. I returned the setting to 6%.

2) I pulled out 8% total fuel. I can barely tell if it helps. However, adding fuel makes the car sluggish.

3) Regarding cat backs, a well respected tuner said that the basic systems were worth only 15 hp. On the other hand, the Borla Stinger was worth about 35 hp.

Another observation is that without a dyno, it's very difficult to determine if small changes to timing or fuel do anything.

Please let me know if you have additional thoughts. Otherwise, I'll keep you posted on any developments.

Russ

You have a PM

 

[RedfireVert]

Originally posted by Pyro
You have a PM

I responded.

 

[bborder]

Russ- I would wait until Shawn from socaldiablo can get your car tuned on the dyno- no point in risking the unknown by changing the settings on the predator.

 

[RedfireVert]

Thanks for the concern...I'm at the point where I can't improve things without an a/f reading. Maybe I'm adventurous or foolhardy for messing with the canned tune. Was simply applying knowledge I gained from years of track tuning a blown 5.0 using a Crane Interceptor, adjustable FMU, and timing light...yeah, the good old days.